From 2005-2009 road engineers Colin Buchanan and Partners conducted traffic flow modelling and measurements in the Kings Cross area on contract to TfL. Buchanans is the daddy of traffic flow engineers and they developed a computer model to analyse the effects of junction changes. Buchanans used the model to predict whether, say making York Way a two-way road would lead to more or less traffic congestion. The Buchanan work has been heavily influential on the design of the new York Way scheme. I am indebted to Sophie Talbot for securing and posting the Buchanan report.

Buchanans May 2009 report is the most comprehensive statistical work on traffic flows Kings Cross except for one respect – TfL advised them to ignore cyclists in their modelling.

‘Following TfL advice, cyclists and motorcyclists were not included in the model as their equivalent PCU values are only a small proportion of the total traffic in the study area.’

This goes some way to explain why the York Way proposals that TfL and the ODA are about to implement are so poor for cyclists and might even make the road more dangerous by increasing traffic flow with no cycle lane. On TfL’s advice, cyclists and their needs weren’t in the model that underpinned the design.

From a statistical perspective, TfL’s advice to Buchanan is odd – they seem to say that because the percentage of two-wheel traffic is low in the overall volume (a PCU is a ‘passenger car unit’) they can be ignored. Despite cyclists comprising 20% of casualties across the Kings Cross junctions. And during the time the Buchanan work was being carried out publicly available figures from DfT showed a sharp increase in cyclists on York Way in both absolute and percentage terms. Competent strategic planning for the next 20 years should accommodate that new trend.

More revealing was what TfL didn’t say – they knew that the cyclist count on York Way was going up, they had a report that said that ‘casualties were inevitable’ but TfL didn’t say to the experts they hired:

‘Cycle safety is really important to us, we need a model that helps people on bikes’

The above is further evidence of TfL’s systemic failure in a duty of care to people, particularly cyclists who use this junction under TfL’s control. And reinforces my desire to see TfL held to account in the courts for corporate manslaughter.

Shouldn’t TfL be tried for manslaughter on these grounds – ‘ignore’ cyclists in re-design of a junction – isn’t that tantamount to professional negligent manslaughter – victims deserved better than this!!

Agree with everything that’s been said. Also puzzled by this PCU idea. Sounds like it’s a counting method that values a car above a cyclist, in terms of through-put. Through-put should count people: whether they be in cars, on bikes or on foot.

There’s nowhere to hide surely. I can’t see any way that TfL could possibly defend a corporate manslaughter charge. The one thing that could possibly redeem them would be to Go Dutch, make the KX area a model of good practice. Go TfL, the gauntlet is down….

@Richenda Walford – I understand your sentiment but you are slightly confused. PCU measures the “value” of a road user in terms of the congestion they create – buses and HGVs are larger and take up more room, and take longer to clear junctions, and therefore have higher PCU values then cyclists and motorcyclists who are more nimble and place less strain on capacity.

There are however, other models that DO seek to place a financial value to road users time. It shouldn’t surprise you that taxi passengers come first in that, and cyclists third from the bottom (see table here on the DfT website).

There has been another study as I always maintain conducted between 2000 and c.a. 2002 for the Kings Cross Cultural Partnership then based in Brittania Walk. Please if anyone has this report we need it, as it also advocated a two traffic flow solution then, including for South of Euston Road gyratory.

Do we know how the DfT derived its “values” of various road users? I can understand how they might have concluded that a taxi passenger has the highest value, as these will tend to be expenses-paid professionals or executives who consider that time is money.

I am certainly not convinced that car drivers/passengers, or public transport passengers, should be valued more highly than cyclists though – in the centre of London at least there are significant numbers of cycle commuters, comprising as much as 35-40% of all vehicles crossing the principal central and east-central Thames bridges, and many of these are senior executives or professionals working in banking, accounting, insurance etc. You can of course quibble about what “value” they truly represent, but in terms of DfT mathematics I am sure they are very high.

Perhaps the table is also distance based? In my experience you can typically cross central London (City and Westminster) on a bike in half the time it takes a car or taxi, ergo less of these expensive people’s time would be wasted on travel this way.

From 2004 …
Create shared zones where possible. It is important to keep
pedestrian and cycle paths together with vehicular traffic, as
these more open, well-used routes are usually safer and more
direct than routes that are completely isolated from the road;
> Provide routes along sensible desire lines, designed to a
standard that makes walking and cycling through the Area and
the Triangle and beyond, easy and efficient. For example, …”cyclists
may be given the right of way over car traffic, or follow straight
lines where car traffic has a more indirect route…”http://www.islington.gov.uk/DownloadableDocuments/Environment/Pdf/kingscross_opportunity_area_brief.PDF

Although not mentioned by TfL in today’s press release, the Bow Roundabout and King’s Cross Gyratory system, both locations where cyclists have been killed in recent months, are the subject of separate review

Another problem here is that the TfL and its consultants seem to focus on data for actual, observable road users, rather than trying to assess how many people (of all modalities) would like to use this junction but do not do so because it feels dangerous to them.

TfL’s typical argument is ‘there’s only a small percentage of cyclists/pedestrians, therefore we cannot justify allocating them any more space’. Could it not be that the small number of cyclists/pedestrians is exactly because they have been allocated so little space?

If TfL did allocate road space for safe cycling, it would reveal a huge suppressed demand. What’s the evidence for this? As flawed as they are, the cycle superhighways have induced new cycling on those routes. Some of this will be cyclists who were previously using other routes, some will be new cyclists altogether. The adage holds for cycling infrastructure in a city like London: if you build it, they will come.

TfL must dispense with its primitive, static modelling and reflect the dynamic realities of traffic and choice of transport mode and route. Many cyclists (and potential cyclists) simply avoid major junctions because they feel – and in many cases are – unsafe.

Great reporting on this issue. Citizen journalism at its best. A shame The Times didn’t acknowledge your leg work. What’s new, eh?

This article is very misleading! As a traffic engineer I think its important to put the record straight. The decision to ignore cyclists in a traffic model is not the same as ignoring their safety in the design. The choice to ignore them in the model is related to the fact that cycles have very little impact on the ‘capacity’ of the junction, which is what the model will report. That has absolutely no influence over whether features to safely accommodate cyclists are incorporated in the design. The choice to ‘ignore’ cyclists in a capacity model is very common. Indeed, the junctions with the best possible cycle facilities are likely to have been modelled ‘ignoring’ cyclists.

The DfT’s values of time are based on national average figures. Therefore the cycling value of time doesn’t work for London. London is unusual within the UK because cycling is quicker for many centre-of-town journeys and so used by people who want to get somewhere fast (i.e. have a high value of time). Whereas say in Nottingham or Leeds cycling is slower and so used by people who are in less of a rush (i.e. value their time less).